Crack! NOOOO I cringe! There is no worse sound in the world to someone who is canning: The cracking of a jar you just so carefully packed. I hate it when the second you put them in the boiling water they crack….darn it! So much wasted time and work. Yes, I know I have some jars that are a little older–and maybe I just need to replace all of them so that this won’t happen. The problem is I can’t tell my old jars from my new jars. Oh well.